[Role of afferent C fibers in electroacupuncture of "zusanli" point in activating nucleus raphe magnus].
The purpose of the present work is to study whether the analgesia of "Zusanli" EA was mainly produced by its noxious effect. The antidromic C waves on N. peroneus communis innervating the area of "Zusanli" point were recorded. When "Zusanli" point was stimulated by trains of stimuli, the amplitude of the antidromic C wave was obviously decreased due to collision with the orthodromic stimulation. It was suggested that EA of "Zusanli" could excite some C fibers. It was observed that when the stimulation intensity reached the threshold of C fiber, the NRM neurons were obviously activated, and when it reached or exceeded the intensity for producing the maximal C wave, the NRM neurons were highly activated. Therefore, EA analgesia is probably produced mainly by its noxious stimulus component, especially carried by C fibers, via a negative feedback mechanism in modulating pain.
Liu
X A
XA
Institute of Acupuncture and Moxibustion, China Academy of Traditional Chinese Medicine, Beijing.
Jiang
M C
MC
Huang
P B
PB
Zou
T
T
D015667:Acupuncture Analgesia; D015669:Acupuncture Points; D000344:Afferent Pathways / Q000502:physiology; D000818:Animals; D002415:Cats; D015671:Electroacupuncture; D005260:Female; D008297:Male; D009412:Nerve Fibers / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D010146:Pain / Q000503:physiopathology; D011903:Raphe Nuclei / Q000502:physiology*; D051381:Rats